Ambrosia tomentosa Nutt.  
Family: Asteraceae
burragweed,  more...
[Franseria discolor Nutt.,  more]
Ambrosia tomentosa image
Max Licher  
Perennials, 10-30+ cm. Stems erect. Leaves mostly alternate; petioles 8-25(-35+) mm; blades elliptic to lance-elliptic, 50-80(-180+) × 12-20(-50+) mm overall, (1-)2(-3)-pinnately lobed (lobes ± deltate), bases cuneate, ultimate margins with ± deltate teeth, abaxial faces densely finely scabrellous (silvery gray), adaxial faces strigillose. Pistillate heads clustered, proximal to staminates; florets (1-)2. Staminate heads: peduncles 2-9 mm; involucres saucer-shaped (with black nerves), 3-6+ mm diam., strigillose; florets 25-40+. Burs: bodies ± pyriform, somewhat flattened, 1.5-2.5(-4) mm, finely scabrellous, spines (1-)8-12+, scattered, stoutly conic, 0.5-1+ mm, tips straight. Flowering Jun-Sep. Seasonally wet clays or sands, disturbed sites; (200-)1200-2100 m; Ariz., Colo., Idaho, Ill., Iowa, Kans., Mo., Mont., Nebr., N.Mex., N.Dak., S.Dak., Tex., Utah, Wis., Wyo.
Ambrosia tomentosa image
Max Licher  
Ambrosia tomentosa image
Max Licher  
Ambrosia tomentosa image
Max Licher  
Ambrosia tomentosa image
Intermountain Herbarium (UTC)  
More Images        Web Links       View Parent Taxon       Close window